Multi-lumen catheters are used for a variety of applications where it is necessary to have two or more separate fluid pathways. One such application for a multi-lumen catheter is for use in hemodialysis. During hemodialysis, a dual-lumen catheter can be employed to simultaneously accommodate opposing blood flow. More specifically, one lumen aspirates blood from a blood vessel of a patient to a dialysis machine where it is processed for the removal of toxins, while the other lumen infuses the purified blood to the patient.
The primary problem in many dialysis catheters is that related to clotting and fibrin sheath formation. Thrombus and fibrin can occlude distal tips of the catheter lumens, resulting in loss of catheter function when such an occlusion prevents blood flow. This typically occurs initially in the arterial lumen used for aspiration of blood from a patient. A secondary problem is that related to the arterial lumen “sucking” against the vessel wall in which it resides. This problem can occur if the arterial lumen ports become fully occluded by the patient's vasculature. When either of the aforementioned problems is observed clinically, the first attempt at salvaging the catheter is to reverse the bloodlines (i.e., to aspirate through the longer lumen, and to infuse through the shorter lumen, contrary to normal blood flow). While such a scenario causes cleaned blood to flow directly toward the lumen that is under vacuum, line reversal in certain catheters can result in inefficient flow (high re-circulation).
Accordingly, an object of the present invention is to provide a dialysis catheter with adequate profile to allow efficient exchange of blood, while preventing problems associated with occlusion. Another object of the present invention is to provide a dialysis catheter with a moveable lumen so that post-placement adjustment is possible. Further objects and advantages of the present invention will become apparent from the ensuing description and drawings.